Clarification of beverages



' r' Feb. 3, 19o9 w. E. WALLES ET AL 2,872,321

CLARIFICATION 0F BEVERAGES Filed May 7, 1958 INVENTORS. Wf//re/m E.Wa//es Patented Feb. 3, 1959 CLARIFICATION F BEVERAGES Wilhelm E. Wallesand Wiiliam F. Tonsignant, Midland,

Mich., assignors to The Dow Chemical Company, Midland, Mich., acorporation of Delaware Application May 7, 1958, Serial No. 733,741

8 Claims. (Cl. 99--48) The present invention relates to the treatment ofvarious essentially clear or limpid beverages to materially improvetheir clarity and transparency or translucence and to render them stableagainst development of haze subsequent to treatment. The invention hasparticular reference to the low temperature clarification of manybeverages. It is especially concerned with such treatment for theseveral alcoholic malt beverages and the like, including beer, ale,porter and so forth.

Many essentially clear liquid beverages, or beverages intended to be ofan essentially clear or limpid character, are liable to be obtained intheir as-manufactured state with some degree of haziness or cloudinessthat persists despite filtration, or to develop such a condition uponstanding or being chilled, or both. lt is quite common, of course, forbeverages to be stored, sometimes under refrigeration, after theirmanufacture. Besides, they are frequently chilled prior to consumptionto enhance their palatableness. Such haziness, including hazing onstanding and chill haze, occurs frequently in the several essentiallyclear or limpid beverages, both non-alcoholic and alcoholic in nature,that are derived from various grains, fruits, berries and vegetables ormixtures thereof. Of course, most of the alcoholic beverages areprepared by fermentation processes and are often obtained as distilledor spirit fortified products. in addition, many beverages are oftencarbonated, either by natural or artificial means, and may often beartificially sweetened with sugar or other saccharine materials.

Hazing in essentially clear beverages is generally believed to beprimarily caused by pectins and tannins and the like (whose solubilitiesmay range from being completely insoluble to completely solublesubstances and which may be colloidal or otherwise efficientlydispersible materials), as well as other dark colored soluble orpartially soluble materials that are obtained in the beverage during itsmanufacture. In some instances, proteinous constituents may also beresponsible for the hazing phenomena in beverages, it has been proposed,for example, that a protein tannin complex in beer, which frequentlycontains traces of such heavy metals as copper and iron, is responsiblefor clouding, particularly chill hazing, of the beverage. Such complexesare also felt to be responsible for of-avors in the beer and the likemalt beverages because of their propensity to induce oxidation of someconstituents of the beverage or due to organic reduced sulphur in thecomplex, or both. Insoluble constituents, including a large part, or allof the completely insoluble pectins and tannins, can ordinarily beremoved quite readily from a beverage by ordinary filtration procedures.Such physical treatment, however, does not accomplish removal of thesoluble or eiciently dispersed pectins, tannins and other dark coloredsubstances (which frequently are of high molecular weight and which maybe relatively unstable in nature), including those in protein complexes,that engender the above-mentioned turbidity and hazing phenomena.Furthermore, the efficiently dispersible pectins, tannins and proteincomplexes may often be responsible for many difficulties inthefiltration of the beverages.

While it is known to clarify various beverages, including maltbeverages, through use of various agents, including water-solublepolymeric agents, that are more or less adapted to coagulate andprecipitate the haze-producing ingredients in the beverage, the usualtreatment is ordinarily accomplished at room temperature with acompletely or substantially completely water-soluble coagulatingmaterial which is capable of remaining in normal aqueous solution at thetemperature desired for treatment. In many cases, the heating of abeverage to temperatures in excess of chilling temperatures, such asthose above about 15 C., may have a deleterious consequence on thequality of the beverage being treated. This is often the case incarbonated beverages, and is particularly so for the various alcoholicmalt beverages, such as beer, etc. Thus, when beer is heatedsubstantially above about 15 C. and maintained for any significantperiod of time at such elevated temperature, it tends to lose itsflavor. In addition, the heating may cause loss of dissolved carbondioxide or other carbonating gas in beer and the like beverages and alsoprovides opportunity for mold or bacterial growth to be engendered inthe beverage being treated.

It would be advantageous, and it is the chief aim and concern of thepresent invention, to provide new and highly efiicacious agents for thetreatment of essentially clear beverages that would be capable ofcoagulating and precipitating therefrom the water-soluble or otherwiseefiiciently dispersible colloidal pectins, tannins and other darkcolored soluble and partially soluble or otherwise dispersiblesubstances that are responsible for producing the hazing phenomena inthe beverage. It would be a corollary advantage of commensuratemagnitude, and it is the principal object of the present invention, toprovide a process for the material clarification and stabilizationagainst hazing of essentially clear beverages using the referred-tonovel coagulating and precipitating agents. It would be of exceptionalbenefit if a clarifying process of the indicated variety could beprovided which would be especially well suited for practice at lowtemperatures without necessitating heating of the beverage being treatedto undesirable temperatures levels. It would be additionallyadvantageous, and it is also an objective of the invention, to provide acoagulating and precipitating agent of the described type and a processfor its utilization in the clarification of beverages that wouldpossibilitate, along with the achievement of the primary end, manyancillary and cognate benefits and desiderations, as hereinafter morefully delineated.

It is to be fully understood, incidentally, that the operability andutility of the present invention is neither dependent upon nor to beevaluated in the light of an exact identification or characterization ofthe substances that cause hazing in beverages. The reference to them asincluding pectins, tannins and proteinous complexes is merely set forthupon the basis of reasonable information and belief. And, as ishereinafter demonstrated, such substances, regardless of their specificnature, are eilicaciously coagulated and precipitated from beverages ofthe indicated type by use of the herein contemplated treating agents.

ln accordance with the practice of the present invention whereby theabove mentioned and hereinafter more specifically manifest objects,advantages and benefits may be achieved, essentially clear or limpidbeverages may be -advantageously treated for removal of pectins,tannins, protein complexes and dark colored soluble materials ofnaturally occurring origin in order to be clarified and rendered stableagainst hazing by a process which cornprises adding to the beveragebeing treated, at a tempera` ture beneath the cloud point of thehereinafter defined treating agent (usually beneath about 4 C.), a minorproportion of, say, between about 0.0001 and 1.0 percent by weight, moreadvantageously from about 0.01 to about 0.1 or 0.2 percent, based -onthe weight of the beverage being treated, of a coagulating andprecipitating agent for the haze and turbidity-inducing ingredients inthe beverage that consists of an N-vinyl-S-ethyl-Z-oxazolidinone polymerof the general structure:

H CzHsC--O (hereinafter, for brevity and convenience, referred to asPVG-E, which, in the following specification and in the hereto appendedclaims, is intended to comprehend, as equivalents, such isomers aspoly-N-vinyl-4-ethyl-2-oxazolidinone andpoly-N-vinyl-4,S-dimethyl-Z-oxazolidinone, or mixtures of either or bothwith one another or with poly-N-vinyl-5-ethyl-2-oxazolidinone), whereinn is a plural integer of considerable magnitude (such as one that is inexcess of 50 and usually in excess of 100 or so); warming the beveragebeing treated after addition of the PVO-E to a temperature above thecloud (or thermal coagulation) point of the polymer (i. e., generallyabove about 4 C); then filtering the coagulated and precipitatedturbidity-inducing ingredients, or otherwise physically separating andisolating them from the beverage, along with the precipitated PVO-Etreating agent which is insoluble in the aqueous solution above itscloud point.

The above indicated treating quantities of the PVG-E are not absolutesince, in certain eases, greater or lesser proportions of the agent maybe suitable and effective to employ. Thus, any quantity of the agentthat is in an amount which is adequate to materially precipitate thehaze-inducing ingredients from a given lbeverage may be utilized fromthe practice of the invention. After addition of the PVO-E, the treatedbeverage may be warmed to any desired moderate temperature although,especially in the case of malt beverages, it may be preferable tomaintain it at temperatures beneathabout C. or so. After thehaze-inducing ingredients and the precipitated PVO-E have been isolatedfrom the clarified beverage, the product may be rechilled for storageand handling at any desired lower temperature or, if desired, may bepermitted to remain at the higher temperature. Ordinarily, about 40 C.is usually as high an upper limit of temperature as may be desired forwarming the beverage during the precipitation and filtration or othersolidsisolating step.

The treatment can be performed by directly adding the PVO-E to thebeverage at -a temperature beneath the cloud point of the polymer atwhich temperature the agent is soluble yin aqueous media. Followingaddition of the PVO-E treating agent, the beverage is warmed above thecloud point of the polymer to facilitate the desired coagulation andprecipitation of the pectins, tannins, complexes and other dark coloredsoluble ingredients to occur, along with precipitation of the PVO-Ewhich is insoluble in aqueous media above its cloud point. Tl is isfollowed by removal of the precipitate and recovery of the clarifiedbeverage. After this, as indicated, the beverage may be rechilled, if sodesired. The PVG-E may, of course, be added in the form of an ice watersolution or other aqueous dispersion (preferably as a relativelyconcentrated composition in the liquid vehicle) 'to the beverage beingtreated. It is not necessary in all instances for the PVO-E to be addedto the beverage while the latter is at a temperature beneath the cloudpoint of the PVO-E, so long as the necessary chilling to solubilize thecoagulating and precipitating agent is accomplished tra 4 after additionof the PVO-E has been made to the beverage being treated.

The beverage may be treated at any convenient point in its manufactureor processing adapted to provide or accommodate the manipulativeconditions of the present process. Thus, as indicated, the treatment maybe accomplished when the beverage is suitably cold to be beneath thecloud point of the PVO-E or at some point prior to chilling when thebeverage is not actually cold enough to dissolve the PVG-E. With beer orother malt beverages, for example, the treatment may be made when thebeverage is being racked down from the fcrmentors or when the beer iscommencing its storage in the cold cellars, especially if storage isperformed at temperatures beneath the cloud point of the agent. Theagent can even be added to the beer while it is in the mashing stage ofits manufacture. In such instances, however, relatively greaterquantities of the agent may be required for optimum results.

If desired, the beverage may be agitated or stored during addition ofthe polymer agent or shortly thereafter, or both, in order to ensure aquick and thorough admixture of the coagulating and precipitating agentwith the beverage being treated. This may be especially desirable whenthe beverage is being warmed after addition of the PVG-E to atemperature `above the cloud point or the polymer. While stirring is notan absolute necessity, it may be resorted to for purposes of expeditingthe processing of large volumes of the beverage, especially when thetreatment is made with batch quantities. As is apparent, the PVO-E mayalso be continuously added to a flowing cold stream of the beveragebeing treated which is at a temperature beneath the cloud point of thepolymer, in which case the turbulence of the moving liquid usuallyproduces an intimate incorporation of the agent therein. Of course, thePVG-E can be added to a flowing stream of the beverage at a temperatureabove the cloud point of the polymer if the beverage is chilled afteraddition of the agent to a solubilizing temperature 'beneath the cloudpoint of the PVO-E prior to rewarming of the polymercontaining beveragefor coagulation and precipitation.

Ordinarily, the PVG-E effects coagulation and precipitation in thebeverage of the normally non-filterable pectins, tannins, complexes andother haze-inducing ingredients in a practicallyV instantaneous manner.After warming of the beverage to a temperature above the cloud point ofthe polymeric agent any uncomplexed polymer is also assured of beingremoved from the treated beverage. It is seldom that more than an houris required foi` treating purposes. Generally, only severalminutes-usually less than ten-are all that are necessary for the desiredresult. The precipitate that forms which, especially at temperaturesabove the cloud point of the polymer, is comprised of PVO-E complexesand the water-insoluble polymer itself, generally settles very rapidlyfrom the beverage and is usually quite fiocculent in nature. More often,the precipitate is found to consist of relatively large size particles.

After the coagulation and precipitation of the hazeinducing ingredientshas been accomplished, the precipitate may be isolated or removed andthe clarified beverage recovered by settling and decantation orsiphoning operations or by filtration of the treated beverage. lfpreferred, although there is no absolute requirement to do so,filtration may be accompanied by utilization, in the conventionalmanner, of such filter aids as diatomaceous earth, cellulosic filteraids and the like or their equivalent. Because the treatment of thepresent invention produces good precipitation of haze-inducingingredients from substantially all essentially clear beverages to yielda generally relatively clear supernatant, rapid filtration or otherliquid separation is greatly facilitated with minimized problems ofapparatus maintenance, such as filter cleaning.

The water soluble PVO-E coagulating and precipitating agents used in thepractice of the present invention have a pronounced ability to clarifythe beverages being treated and to stabilize them in a substantiallypermanent manner against hazing, even upon being chilled for prolongedperiods of time. Frequently, the beverage is made remarkably pellucidand transparent by treatment with the PVO-E polymer. In addition, thetaste of many beverages oftentimes appears to actually be improved andappreciably augmented by the treatment. Besides, many spumous of foamybeverages, such as beer and the like, are additionally ameliorated bythe present treatment in having their head of foam (as produced uponpouring) improved in its general physical characteristics includingthickness, appearance and life. Besides, the foam forming ability of atreated spumous beverage, such as beer, is usually also enhanced bypractice of the present invention.

As indicated, either poly-N-vinyl-5-ethyl-2-oxazolidinone or,alternatively, either poly-N-vinyl-4-ethyl-2- oxazolidinone orpoly-N-vinyl-4,5-dimethyl-2-oxazolidinone or mixtures of any or all ofthese isomers which are generally equivalent for the present purpose maybe utilized as the coagulating and precipitating agents in order toaccomplish the treatment of the present invention. None of the PVO-Epolymers that may be employed produce deleterious inuences orintolerable toxicological effects or other undesirable occurrences inthe beverage being treated. Advantageously, the normally solid polymerthat is utilized as a coagulating and precipitating agent for thepresent purposes is a high polymer having a Fikentscher K-value of atleast about 5. More advantageously,v the PVG-E polymer employed has aFikentscher K-value between about and 100. Most advantageously, itsK-value is from about 10 or to 75. The Fikentscher K-'value of apolymeric substance is a quantity, as has been defined by Fikentscher inCellulosechemie, 13, 60 (1932), that represents an approximate measureof the weight fraction of a given sample of polymer in an infinitesimalmolecular weight range. According to a concept that is widely acceptableto those skilled in the art, it may be said to be in correlation, in anexponential manner, to the mean average molecular weight that obtains ina given sample of a polymer substance. The K-value of a water-solublepolymer may be derived, in any given instance, by the formula:

0.000075 K2 1+0.0015 It wherein Z is the relative viscosity of a polymersolution at 1 percent by weight concentration in the solvent at anygiven temperature. For practical purposes, the same K-values for anygiven water-soluble polymer may be determined according to the equationsin U. S. 2,811,449.

The PVO-E that is utilized in the practice of the present invention,including poly-N-vinyl-4-ethyl-2-oxazolidinone,poly-N-vinyl-4,5-dimethyl-2-oxazolidinone and, as indicated, especially,poly-N-vinyl5-ethyl-Z-oxazolidinone, are, for all practical purposes,water-insoluble polymers. Although, within certain narrow limits, PVO- Ewill dissolve in water, its solubility in aqueous media is quiteseriously restricted. Thus, as indicated in the foregoing, the highpolymer forms of PVO-E are generally insoluble in water at temperaturesabove about 34 C. For example, PVO-E having a Fikentscher K- value ofabout will not dissolve to any appreciable extent in water that is atroom temperature or higher. While the polymer can be dissolved in icewater, it comes out of solution by means of thermal coagulation (i. e.,exhibits a cloud point) upon warming of the cold solution totemperatures above about 4 C. At temperatures that are higher than thecloud point of the PVO-E in such cold aqueous solutions, the polymergenerally precipitates from the solvent vehicle and is found to beinsoluble for allfpractical intents therein,

10g z +0001 K As has been indicated, any essentially clearr or limpidbeverage, or one intended to bel of such character, may be benefited bytreatment in accordance with the present invention. Typical of suchbeverages there may be mentioned beer, ale, porter, the various grapeand other fruit or berry wines, champagne, sake, brandy, whisky, gin,vodka, tequila, cider (sweet or hard), such unfermented fruit juices asapple juice, grape juice, prune juice and the like, cranberry juice andother clear berry juices, sweet or so-called soft drinks (bothcarbonated and non-carbonated, either before or after carbonation) andother similar beverages that are desired to be obtained and used in atransparent or translucent, free or substantially free from hazecondition.

To illustrate specic treatments that may be accomplished in the practiceof the invention, apple juice may be advantageously clarified andstabilized against hazing with between about 0.001 and 0.2 percent byweight, based on the weight of the juice, of the PVO-E polymer agent.Preferably at least about 0.003 percent of the agent is used forclarifying apple juice. Beer and wine are effectively enhanced with fromabout 0.001 to 0.1 percent or so of the agent, preferably about 0.005 orso percent. For treatment of beer, this is in the range of fromone-quarter to twenty-five pounds of the treatin-g agent per hundredbarrels (twenty-five thousand pounds) of beer. Frequently it is moredesirable and economical 'to use from one-half to two pounds, moreadvantageously about one pound, of the agent per hundred barrels ofbeer. In the case of most wines and other tannic acidcontainingbeverages, an optimum quantity of the agent to use is frequently anamount that is about equal on a weight basis to the amount of tannicacid in the beverage. As will be readily appreciated, however, specificrequirements may oftentimes be found to vary with particular beers,wines or other beverages being treated. Prune and -grape juice arebeneiicially treated about the same way as apple juice.

In order to further illustrate the invention, the following examples,not intended to be limiting 'or restrictive, are given wherein all partsand percentages are to be taken on a weight basis.

Example A Example B Two parts of the samePVO-E polymer as employed inthe lirst example were dissolved, with stirring, in parts of water at 0C. The PVO-E dissolved completely in the water to form a clear,colorless solution. When the solution was warmed to slightly above about4 C., all of the PVO-E precipitated. Further heating up to about 100 C.did not cause dissolution of the polymer. Cooling of thepolymer-containing aqueous mixture to 3 C. caused all of the polymer toredissolve in order to reobtain the original clear solution. Theforegoing indicates the cloud point in aqueous media of PVO-E. Aboutidentical results are obtained when the procedure is repeated withpoly-N-vinyl-4-ethyl-2-oxazolidinone andpoly-N-vinyl-4,5dimethyl-Z-oxazoldinone.

Example C To about one part of a 2 percent aqueous solution of K-ZOPVO-E at 0 C., there was added 1000 parts of water at 0 C. The resultingclear solution contained the PVO-E in water at a concentration of about0.0002 percent. When the resulting solution was warmed to about 15 C.,it became quite noticeably cloudy. After a relatively short period o fstanding, substantially all of a the` polymer was found to haveprecipitated from the aqueous media, while'the remaining liquid wasperfectly clear. The concentration of PVO-E in the supernate was lessthan 0.001 percent.

Example D To 100 ml. of a commercially obtained bottled beer (CarlingsBlack Label) having an alcohol content of about 31/2 percent there wasadded 1 rnl. of a 2 percent aqueous solution of PVO-E having aFikentscher K-value of 20. Prior to treatment, the beer was cooled to 3C. and maintained at this temperature during the experiment. The aqueoussolution of PVO-E added to the beer was a C. Upon addition of the PVO-Eto the beer, a cloudiness became immediately apparent in the treatedbeverage. This was the result of the complex formed by the polymer andthe haze-inducing ingredients in the beverage. Thus, even without benetof thermal coagulation of the PVO-E, the haze-inducing ingredients ofthe beverage were affected by the PV O-E.

Example E The procedure of the foregoing example was repeated exceptingto employ two samples of the beer and to add only 0.1 ml. of the coldPVO-E solution to each beer sample. Thus, the PVO-E concentration ineach of the samples was about 0.002 percent. One of the samples wasmaintained at 3 C for an hour. warmed to about 15 C. The warmed samplewas appreciably more cloudy than the sample that was permitted to remaincold. After an hour, the warm sample was observed to have a fine anddistinct percipitate on the bottom of the vessel in which it wascontained. The unwarmed sample, which was retained in a chilledcondition, remained cloudy all over without any noticeable collection ofprecipitate at its bottom. Each of the samples was then ltered throughfilter paper while being maintained at the temperature of treatment. TheWarm sample ran through the paper rapidly to yield a perfectly clearbeer. Filtration of the sample that had been maintained chilled was muchslower and the iltered product was noticeably less clear than that fromthe warmed sample. From the foregoing, the advantage of thermallycoagulating the added PVO-E in order to obtain a coarse precipitatewhich can be readily removed from the beer or other beverage beingtreated is readily apparent.

Example F In order to indicate the correllation between concentration ofPVO-E coagulating and precipitating agent and cloudiness of the treatedbeverage product, the general procedure of the foregoing example isrepeated with varying concentrations of the agent in beer. In order toillustrate the effect on the quantitative basis, the percentage of lighttransmission of each sample, as compared to an identically containedvolume of untreated beer, is spectrophotometrically determined usinglight from a standard tungsten filament bulb source that is passedthrough a blue light lter effective in the 425 millimicron range. Theapparatus employed is a Fisher Nefluoro- Photometer. The results aregraphically depicted in the sole figure of the accompanyin-g drawing.The improvement achieved through the use of optimum quantities of PVG-Ewithin the indicated ranges in the practice of the present invention isobvious upon analysis of the therein contained data, in which greatertransmissi-on percentages are proportional to and representative ofgreater clarity. The dotted portion of the curve indicates most rapidllocculation of the haze-inducing ingredients from the beer and optimumprecipitate forming conditions for most efficient filtration.

Example G To indicate the probable character or nature of theingredients that are coagulated and precipitated from beverages by thePVD-E polymers, a series of aqueous The other was solutions of variousnatural products and chemicals is treated with minor proportions ofPVC-E to observe whether or not precipitation will occur. The liquidstreated and the results obtained are set forth in the followingtabulation wherein the symbol f indicates formation of a precipitate anda blank space indicates no result.

Aqueous liquid treated:

Bacteria suspensions- Yeat suspension Staphylococci suspension Cowstomach rumen Proteins- Egg albumin Beef broth Beef heart extract Agaragar X Peptone Amino acids- N-acetyl phenyl glycine Hydrolyzed vegetableprotein X Carbohydrates-gums- Soluble starch Precipitating effect Fromthe foregoing it would appear that the haze-inducing ingredients thatare precipitated by the PVO-E polymeric agents are probably more likelyto be pectins, tannins or proteinous complexes than unmodified proteinsor carbohydrates.

Excellent results similar to those obtained in the foregoing areachieved when the present invention is practiced by substantialduplication of the above experiments with such beverages as unfermentedapple juice (canned or fresh), wine, grape juice, prune juice and otherof the essentially clear and limpid beverages indicated in the foregoingspecification and description.

What is claimed is:

l. Process for treating essentially clear beverages to materiallyclarify them and render them stabilized against hazing which processcomprises adding to the beverage being treated, at a temperature beneathabout 4 C., a minor proportion of between about 0.0001 and l percent byweight, based on the weight of the beverage, of anN-vinyl-S-ethyl-Z-oxazolidinone polymer as a coagulating andprecipitating agent for haze-inducing ingredients in the beverage;warming the beverage containing said polymer to a temperature aboveabout 4 C., whereupon the haze-inducing ingredients are coagulatcd andprecipitated from said beverage along with said polymer; then physicallyseparating the coagulated and precipitated materials from the clarifiedbeverage product.

2. The process of claim 1, wherein between about 9 0.001 and 0.02percent of said N-vinyl-5-ethy1-2oxazo1idinone polymer is added to saidbeverage.

3. The process of claim l, wherein said N-vinyl-S- ethyl-Z-oxazolidinonepolymer has a Fikentscher K-value between about 10 and 75.

4. The process of claim 1, wherein said beverage is a malt beverage.

5. The process of claim 1, wherein said beverage is beer.

6. The process of claim 1, wherein said beverage is an unfermented fruitjuice.

7. The process of claim wherein said beverage is a wine.

8. The process of claim l, wherein said coagulated and precipitatedmaterials are removed from said clarified beverage by filtering.

No references cited.

UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No.2,872,321 19599 Wildeim et It is hereby certified that error appears inthe printed specification of the' above numbered patent requiringcorrection and that the said Letters Patent should read as correctedbelow.

Column 6, line' '72, :for "0.00022" reed u 0.0922 n; oolumr 8, line Til,for "Yeat" read Yeefet m.

Signed end sealed thie, Lith of @catcher 19.59

(C SEAL) Attest:

EARL E'. AELTNE- ROBERT C. WATsoN Attesting OHicer Commissioner ofPatents

1. PROCESS FOR TREATING ESSENTIALLY CLEAR BEVERAGES TO MATERIALLYCLARIFY THEM AND RENDER THEM STABILIZED AGAINST HAZING WHICH PROCESSCOMPRISES ADDING TO THE BEVERAGE BEING TREATED, AT A TEMPERATURE BENEATHABOUT 4*C., A MINOR PROPORTION OF BETWEEN ABOUT 0.0001 AND 1 PERCENT BYWEIGHT, BASED ON THE WEIGHT OF THE BEVERAGE, OF ANN-VINYL-5-ETHYL-2-OXAZOLIDINONE POLYMER AS A COAGULATING ANDPRECIPITATING AGENT FOR HAZE-INDUCING INGREDIENTS IN